The present invention is generally directed to imaging processes with toner and developer compositions, and more specifically the present invention is directed to processes for maintaining the conductivity of magnetic image character recognition developers by the addition of certain components thereto, such as waxes, and imaging and printing processes thereof. In one embodiment of the present invention there are provided processes for obtaining MICR toners and developers with a conductivity of from about 10.sup.-7 to about 10.sup.-12 ohm.sup.-1 -cm.sup.-1 measured, for example, at 10 volts in a cell, which toners can be selected for generating documents, such as checks including, for example, dividend checks, turn around documents such as invoice statements like those submitted to customers by American Express and VISA, corporate checks, highway tickets, identification badges, rebate checks, other documents with magnetic codes thereon, and the like, with no toner smearing. More specifically, in one embodiment the process of the present invention is accomplished by adding Polywaxes, such as POLYWAX 2000.TM. available from Petrolite Corporation, to a toner comprised of resin particles, and magentite particles, such as Mapico Black, which toners are rendered conductive by the wax, and wherein the toners can be selected, for example, for the Xerox Corporation 4090.TM. magnetic character recognition process. Some advantages associated with the imaging processes of the present invention include a toner with stable conductivity characteristics, and wherein image smearing and offsetting of the toner can be avoided, or minimized to read and write heads, including offsetting to the protective foil that may be present on the aforesaid heads in magnetic ink character recognition processes and apparatus inclusive of, for example, the read and write heads present in MICR (magnetic ink character recognition) reader/sorters such as the commercially available IBM 3890.TM., NCR 6780.TM., reader/sorters available from Burroughs Corporation, and the like. Some of the reader/sorter printers contain protective foils thereon, reference for example the IBM 3890.TM., and the problems associated with such protective foils as illustrated herein with respect to read and write heads with no foils are alleviated with the processes of the present invention. Accordingly, with the processes utilizing the toner and developer compositions illustrated the problems of image smearing to, and offsetting from the read and write heads in magnetic ink character recognition apparatuses can be substantially eliminated in embodiments thereof. Moreover, in another embodiment the present invention is directed to improved economical processes for generating documents, such as personal checks, with conductive toners with a Polywax suitable for magnetic image character recognition wherein image smearing and toner offsetting, including offsetting to read and/or write heads including those with protective foils thereon, or unprotected heads as indicated herein is avoided or minimized when such documents are processed in the aforementioned reader/sorters. The toner compositions obtained with the processes of the present invention in an embodiment are comprised of resin particles, pigment particles, including magnetic components such as magnetites, and certain waxes, such as POLYWAX 2000.TM., present in an amount of from about 1 to about 10 weight percent depending on the conductivity desired for example. There are also provided in accordance with the present invention processes for obtaining positively or negatively charged toner compositions comprised of resin particles, pigment particles, Polywaxes, and charge enhancing additives. In addition, the present invention is directed to processes with developer compositions comprised of the aforementioned toners, and carrier particles.
With further respect to the present invention, the process is particularly applicable to the preparation of conductive developers for the generation of documents including personal checks, which have been fused with soft roll fusers. Fuser rolls such as silicon rolls or other conformable fuser rolls, reference for example the soft fuser rolls incorporated into the Xerox Corporation 4040.TM. machine, are useful with the processes of the present invention.
The documents, including the personal checks mentioned herein, can be obtained, for example, by generating a latent image thereon and subsequently developing the image, reference U.S. Pat. No. 4,517,268, the disclosure of which is totally incorporated herein by reference, with the toner and developer compositions illustrated herein. The developed image that has been created, for example, in the Xerox Corporation 9700.TM. MICR printer, reference the aforesaid '268 patent, contains thereon, for example, the characters zero, 1,2,3,4,5,6,7,8, and 9, and up to four symbols (E-13B and CMC-7 font), which characters are magnetically readable by the IBM 3890.TM., or other similar apparatus. One of the problems avoided with the processes of the present invention is to eliminate or reduce the offsetting of the toner as indicated herein to the read and write heads in the apparatus selected for this purpose such as the IBM 3890.TM..
Developer and toner compositions with certain waxes therein are known. For example, there are disclosed in U.K. Patent Publication 1,442,835, the disclosure of which is totally incorporated herein by reference, toner compositions containing resin particles, and polyalkylene compounds, such as polyethylene and polypropylene of a molecular weight of from about 1,500 to 6,000, reference page 3, lines 97 to 119, which compositions prevent toner offsetting in electrostatic imaging processes. Additionally, the '835 publication discloses the addition of paraffin waxes together with, or without a metal salt of a fatty acid, reference page 2, lines 55 to 58. In addition, many patents disclose the use of metal salts of fatty acids for incorporation into toner compositions, such as U.S. Pat. No. 3,655,374. Also, it is known that the aforementioned toner compositions with metal salts of fatty acids can be selected for electrostatic imaging methods wherein blade cleaning of the photoreceptor is accomplished, reference U.S. Pat. No. 3,635,704, the disclosure of which is totally incorporated herein by reference. Additionally, there are illustrated in U.S. Pat. No. 3,983,045 three component developer compositions comprising toner particles, a friction reducing material, and a finely divided nonsmearable abrasive material, reference column 4, beginning at line 31. Examples of friction reducing materials include saturated or unsaturated, substituted or unsubstituted, fatty acids preferably of from 8 to 35 carbon atoms, or metal salts of such fatty acids; fatty alcohols corresponding to said acids; mono and polyhydric alcohol esters of said acids and corresponding amides; polyethylene glycols and methoxy-polyethylene glycols; terephthalic acids; and the like, reference column 7, lines 13 to 43.
Described in U.S. Pat. No. 4,367,275 are methods of preventing offsetting of electrostatic images of the toner composition to the fuser roll, which toner subsequently offsets to supporting substrates such as papers wherein there are selected toner compositions containing specific external lubricants including various waxes, see column 5, lines 32 to 45.
In a Petrolite, Inc. brochure, dated 1985 there are disclosed polymeric hydroxy waxes, which brochure indicates that the waxes may have utility as toner.
In U.S. Pat. No. 4,517,268, the disclosure of which is totally incorporated herein by reference, there is illustrated a process for generating documents such as personal checks suitable for magnetic image character recognition, which process involves generating documents in high speed electronic laser printing devices. The developer composition disclosed in this patent is comprised of, for example, magnetic particles, such as magnetite, certain styrene resin particles, and the carrier particles as illustrated in the Abstract of the Disclosure. Additive particles may also be included in the developer compositions of this patent.
Moreover, toner and developer compositions containing charge enhancing additives, especially additives which impart a positive charge to the toner resin, are well know. Thus, for example, there is described in U.S. Pat. No. 3,893,935 the use of certain quaternary ammonium salts as charge control agents for electrostatic toner compositions. There is also described in U.S. Pat. No. 2,986,521 reversal developer compositions comprised of toner resin particles coated with finely divided colloidal silica. According to the disclosure of this patent, the development of images on negatively charged surfaces is accomplished by applying a developer composition having a positively charged triboelectric relationship with respect to the colloidal silica. Further, there are illustrated in U.S. Pat. No. 4,338,390, the disclosure of which is totally incorporated herein by reference, developer and toner compositions having incorporated therein as charge enhancing additives organic sulfate and sulfonate compositions; and in U.S. Pat. No. 4,298,672, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions containing resin particles and pigment particles, and as a charge enhancing additive alkyl pyridinium compounds, inclusive of cetyl pyridinium chloride.
Other prior art disclosing positively charged toner compositions with charge enhancing additives include U.S. Pat. Nos. 3,944,493; 4,007,293; 4,079,014 and 4,394,430.
More specifically, illustrated in U.S. Pat. No. 4,859,550, the disclosure of which is totally incorporated herein by reference are magnetic character recognition processes which comprises the generation of a latent image and developing the latent images with a toner composition comprised of resin particles, pigment particles, magnetic particles, such as magnetite, and an additive component comprised of an aliphatic hydrocarbon, or polymeric alcohols of the formula EQU CH.sub.3 (CH.sub.2).sub.n CH.sub.2 OH
wherein n is a number of from about 30 to about 500, and preferably 300. Another embodiment of the aforementioned patent is directed to an electrophotographic process for obtaining images, which comprises the generation of a latent image in an electronic printing device; thereafter developing the characters with a toner composition comprised of resin particles, pigment particles, magnetite particles, and an additive component comprised of an aliphatic hydrocarbon or polymeric alcohols of the formula EQU CH.sub.3 (CH.sub.2).sub.n CH.sub.2 OH
wherein n is a number of from about 30 to about 300, and subsequently processing the documents with magnetic characters thereon in reader/sorters. Also, in a further embodiment of the aforementioned patent there is provided a xerographic process, which comprises forming a latent image on an imaging member; developing the image with a toner composition comprised of resin particles, magnetite particles, and pigment particles; subsequently transferring the image to a suitable substrate; fixing the image thereto; simultaneously, or thereafter applying to the developed image an aliphatic hydrocarbon or a polymeric alcohol of the formula EQU CH.sub.3 (CH.sub.2).sub.n CH.sub.2 OH
wherein n is a number of from about 30 to about 500, and preferably 300; and subsequently processing the documents with magnetic characters thereon in a reader/sorter. The aforementioned developed images, especially personal checks with magnetic characters thereon, can then be utilized in a reader/sorter without offsetting and image smearing as indicated herein.
In a patentability search report there were recited the following U.S. Pat. Nos. 4,513,074, which discloses a conductive magnetic brush developer and wherein there is included in the toner a polyolefin wax to prolong the life of the developer, and note Example 7 wherein the toner includes 7 percent of an olefin; 4,556,624 directed to a magnetic toner containing an olefin wax; 4,557,991 directed to a magnetic toner containing a polyolefin wax; and 4,681,829 and 4,758,493 which disclose the use of polyolefin waxes, about 2 to 7 weight percent in toners. The disclosures of each of the aforementioned patents are totally incorporated herein by reference.